Pinpoint Test P: STRAIGHTLINE Driveline Wind-Up
WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
4x4 high/low (4H/4L) is not intended for driving on hard/dry surfaces.
- P1 VERIFY THE CONCERN
- Drive the vehicle and shift from 2H to 4H. There should be minimal wind-up in 4H mode during straight line maneuvers, (wind-up in turns is normal; 4x4 high/low is not intended for driving on hard/dry surfaces).
- Is excessive wind-up present?
- YES : Go to P2.
- NO : RETURN the vehicle to the customer. ADVISE about correct 4WD system operation and normal vehicle behavior.
- P2 CHECK FOR MATCHING WHEEL AND TIRE SIZES
- Check the wheel and tire sizes.
- Do the 4 wheel and tire sizes match?
- YES : Go to P3.
- NO : ADVISE the customer that 4WD systems require 4 matched, correctly inflated, correctly maintained tires to operate correctly.
- P3 CHECK TIRE WEAR
- Check each of the 4 tires for wear.
- Are the 4 tires worn evenly?
- YES : Go to P4.
- NO : ADVISE the customer that 4WD systems require 4 matched, correctly inflated, correctly rotated tires to operate correctly.
- P4 CHECK TIRE INFLATION PRESSURE
- Check the inflation pressure in each tire. Refer to vehicle certification label.
- Are the tire inflation pressures correct?
- YES : Go to P5.
- NO : ADJUST the tire pressure as necessary. TEST the vehicle for normal operation. ADVISE the customer that 4WD systems require 4 matched, correctly inflated, correctly maintained tires to operate correctly.
- P5 CHECK THE FRONT AND REAR AXLE RATIOS
- Check that front and rear axle ratios match. Refer to FRONT DRIVE AXLE/DIFFERENTIAL article.
- Do the front and rear axle ratios match?
- YES : RETURN the vehicle to the customer and ADVISE about correct 4WD usage and normal vehicle behavior.
- NO : CHECK the vehicle identification label. INSTALL the correct axle(s). REFER to DRIVELINE SYSTEM - GENERAL INFORMATION article.